Chusetts



(No Model.

R. L. CARR & 0. YARWOOD. STEAMABOILER.

Patented NOV. 22, 1887 iliil'ina-e valliarivvvz N. PETERS. Phnmumiw n hr, yvmm mn. D. a

UNITED STATES PATENT OFFICE.

ROBERT L. CARE AND MATTHEW O. YARYVOOD, OF FALL RIVER, MASSA- CHUSETTS,ASSIGNORS OF ONE-THIRD TO ALBERT E. BOSWORTH, OF

SAME PLACE.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 373,798, dated November22,1887.

Application filed March 18, 1887.

To all whom it may concern.-

Be it known that we, ROBERT L. CARR and MATTHEW G. YARwooD, both of FallRiver, in the county of Bristol and State of Massachusetts, haveinvented certain new and useful Improvements in Steam-Boilers; and we dohereby declare that the following specification, taken in connectionwith the drawings furnished and forming a part of the same, is a clear,true, and complete description of the several features of our invention.

The prime object of our invention is to economize in fuel by affordingspecial opportunities for the direct conduction of heat from below thecrown-sheet to the water overlying said sheet at its lower end.

After describing our said improvements in connection with the drawings,the features deemed novel will be specified in the several clauses ofthe claim hereunto annexed.

Figure 1, in section, illustrates the fire-box end ofa steam-boilerembodying our improvements in a desirable form. Fig. 2 is a top view ofa portion of the crown-sheet shown in Fig. 1. Fig. 3 is an enlargedsectional view of aportion of the crown-sheet, one of theheating-chambers,and a droprtube combined therewith. Fig. 4, in section,illustrates a portion of a crown-sheet, a heating-chamber, and adrop-tube pendent within and below said chamber.

In Fig. 1, A denotes the boiler, a the firebox, b the crown-sheet, and cthe water-space above the crown-sheet; and it is to be understood thatwhile we here represent the fire-box end of a horizontal boiler, thecharacter of the boiler, as to its form and structure, and in thearrangement of the fire-box and the flues or equivalent tubes, may bewidely varied without in any manner affecting our invention.

We have illustrated several different arrangements of drop-tubespossessing, as a common characteristic feature, sides or walls whichconstitute, also, portions of the sides or walls of theheating-chambers.

In Fig. 3 it will be seen that the drop-tube e is pendent from thecrown-sheet b, and that it has a globular water-chamber, e, at its lowerend; also, that the globular air-heating cham- Scrial No. 231,355. (Nomodel.)

ber d is above the crown-sheet, and has a long tubular neck, d, withinsaid tube 6, and also within the globular water-chamber, and that saidneck d is open at its lower end, and therefore freely accessible to theentrance of heat. In this instance the sides or walls of the neck dconstitute the interior walls of the droptu be, which is thereforeannular in crosssection.

In Fig. 4 the heating-chamber cl, as before described, is mounted on thecrown-sheet b and occupies the waterspace; but the top of said chamberis perforated for receiving the drop-tube 6, having the globularwater-chamber e at its foot, and, as in Fig. 3, the sides or walls e" ofthe drop-tube also constitute portions of the walls or sides of theheatingchamber, which in this instance is annular in cross-sectionbecause of the presence of the drop-tube.

In boilers wherein heavily-forced drafts are employed-as, for instance,with locomotiveboilersit is well known that drop-tubes are speciallyliable to be cutaway by the abrasive contact of sparks or cinders, andit is in this connection, it will be seen, that the droptubes can bepractically protected against said abrasive effects by locating themwholly within the heating-chambers, as illustrated in Fig. 5, whereinthe lower end of the drop-tube e is above the plane of the crown-sheetb, and, as in the other illustrated forms, the sides or walls 0 of saidtubes constitute also a portion of the Walls or sides of theheating-chamber d,

which is annular in cross-section.

With our novel combination of drop-tube and heating-chamber it will beseen that we obtain not only an extraordinary area for the favorableconduction of heat to the water above the crown-sheet, but also theadvantage of heating detached but communicating bodies of water withinthe drop-tubes. It should also be observed that with the drop-tubes, asused by us, the well-known interior circulatingtubes-may be employedwithout in any manner affecting our invention-as, for instance, asillustrated in Fig. 4, wherein a circulatingtube, f, is shown, of theusual form, it being obvious that similar circulating-tubes may beemployed with like results, with drop-tubes having the globularwater-chambers shown in Figs. 1 and 3.

Having thus described our invention, we claim as new and desire tosecure by Letters Patent 1. In a steam-boiler, the combination, with thecrown-sheet, of a drop-tube open at one end into the water-space andclosed at its other end, and a heating-chamber closed at one end withinthe water-space below the water-line and open at its opposite end intothe fire-box, said tube and chamber being concentric to each other,substantially as described.

2. In a steam-boiler, the combination, with the crown-sheet, of adrop-tube open at one end into the water-space and closed at the otherend within the fire-box, and a heating-chamber extending through saiddrop-tube and into the water-space, being closed at its upper end withinthe waterspaee and open at its lower end within the fire-box,substantially as described.

3. In a steam-boiler, the combination, with the crown-sheet, of adrop-tube open at one end into the water-space and closed at the otherend within the fire-box, anda heating-chamber extending through saiddrop-tube and into the water-spaee, being closed at its upper end withinthe water-space and open at its lower end within the fire-box, saidheatingehamber being provided at its closed end with a globularenlargement within the waterspace, substantially as described.

4. In a steam-boiler, the combination, with the crown-sheet, of adrop-tube open at one end into the water-space and closed at the otherend within the firebox, and aheating-chamber extending through saiddrop-tube and into the water-space, being closed at its upper end withinthe water-space and open at its lower end within the fire-box, saiddrop-tube and heating-chamber being provided with globular enlargementsat their closed ends,respectively, substantially as described.

5. In a steam-boiler, the combination, with the crown-sheet, of adrop-tube open at one end into the water-space and closed at its otherend, a heating-chamber closed at one end within the water-space belowthe water-line and open at its opposite end into the fire-box, said tubeand chamber being one within the other, and a circulating-tube withinthe droptube, substantially as described.

6. In a steam-boiler, the combination, with the crown-sheet, ofaheating-chamber proj ecting above said sheet into the water-space, saidchamber being closed at its upper end below the water-line and open tothe entrance of heat from below, and a pendent drop-tube having sides orwalls which constitute portions ofthe sides or walls of saidheating-chainber, substantially as described.

' ROBERT L. CARR.

MATTHFAV G. YARVVOOD.

Vitnesses:

'1. R. VESTAL, DAVID F. SLADE.

